Leaving it all behind
by HarrytheAvenger
Summary: Harry defeats Voldemort in the department of Mysteries and decides he's had enough with the wizarding world and leaves it behind to go to America with his godfather Sirius. But what happens when Harry crosses paths with our favourite NCIS team? No Horcruxes! Sirius lives! Kelly&Shannon live! Rated T to be safe. Harry/Kelly in later chapters.
1. Chapter 1

**Disclaimer: ****I don't own either Harry Potter and NCIS. If I did, it wouldn't be nowhere near as good as it is.**

**Hello all! Was thinking of writing a Harry Potter/NCIS Crossover and this is what I thought of for a start. This is my first ever story which I would appreciate feedback on. Please don't be disrespectful though, still have a lot to learn! Thanks !**

**UPDATE: 07/05/2014 Made the fight scene a little bit longer, hopefully more interesting, as always, let me know what you think. Chapter 2 will be up soon.**

**Summary: **Harry defeats Voldemort in the department of Mysteries and decides he's had enough with the wizarding world and leaves it behind to go to America with his godfather Sirius. But what happens when Harry crosses paths with our favourite NCIS team? No Horcruxes! Sirius lives! Kelly&Shannon live! Rated T to be safe. Harry/Kelly in later chapters.

The battle is in full swing. Members of the Order of the Phoenix and the death eaters were fighting left right and centre. Tonks was fighting Bellatrix, Moody fighting Rodolphous and Lupin was fighting Dolohov. In the middle, near the veil, Harry and Sirius were fighting Lucius Malfoy. A thin layer of sweat covered Harry's face as he battled to protect both himself and Sirius from Lucius's deadly spells.

"Stupefy!" Harry shouted, hoping to distract Lucius enough so Sirius could find an opening. The spell bounced harmlessly off of Lucius's shield and began to laugh.

"Do you really think a simple stunning spell would finish me Potter. Ha-Ha-Ha! It seems the dark lord was right not to think off you as a superior opponent!" Lucius sneered back, unaware of Sirius getting ready to strike.

"Maybe," Harry replied. "Or maybe I'm just distracting you from who you should be keeping an eye on. NOW SIRIUS!" Before Lucius could react to the sentence, he was struck with a powerful bone breaking spell. He screamed and hit the floor with a painful thud.

"Brilliant Harry!" Sirius exclaimed. Harry was about to reply, but before he could, saw a dark red spell hit Sirius in the chest, sending him hurling towards to veil. Time seemed to slow down in Harry's eyes as he saw Sirius arch in the air and knocked unconscious, missing the veil by a fraction of a millimetre. Sirius was struck down, by the women who was currently cackling like the mad witch that she is. Before Harry could react, strong arms circled him.

"Calm down Harry, she's not worth it." Lupin's voice spoke in his ear, but he could barely hear. His anger was getting the better of him.

"She hurt Sirius!" I'm going to kill her for it!" Before Lupin could reply, he was sent flying back by Harry's magic, no longer in control. Harry ran after her, hoping to get some revenge on her for taking his godfather. He could hearing her laughing in the distance, chanting "I killed Sirius Black!" This just made him all the more angrier as he sped up, hoping to catch her. He came to the spinning room, mixing the doors up confusing him as to which way he should go.

"I need to get to the Atrium quickly!" Harry shouted, hoping that he can catch her before she could get away. The doors span again and then stopped as a door in front of him opened. Amazed by what just happened, Harry quickly made his way to the elevator. In no time at all, he got to the Atrium and saw her sprint to one of the fireplaces of the other side.

"Crucio!" he exclaimed pointing his wand at Bellatrix's back. It found the target and sent her flying, but no screams were heard. Instead she was laughing and back on her feet.

"You call that an unforgivable boy! That was pathetic. Let me show you how it's really done. Crucio!" The spell came towards Harry at high speeds, but managed to dodge to the left.

"Accio Prophecy!" Bellatrix used the spell while Harry dodged, but no small ball came towards her. "Accio Prophecy! Accio Prophecy! ACCIO PROPHECY!" Still no small ball came zooming in the air which in turn made Harry laugh loud.

"You don't get it do you! It smashed back in the death chamber!" Harry enjoyed the look on her face turn from anger to fear.

"No! You're lying! You have to be! It's not my fault master, it's not!" Bellatrix said, with fear laced in her voice.

"What are you shouting him for? He can't hear you from here!" Harry laughed again.

"Can't I, Potter!" a cold voice said from behing. Harry turned. There, right in front of him, was the most feared man in all of the wizarding world, Lord Voldemort.

"So, you smashed the prophecy did you Potter? He speaks the truth Bellatrix, which makes me very angry indeed. How did you manage to get thwarted by a few school students? You've disappointed me for the last time Bella." Voldemort pointed his wand at her. "Avada Kedavra!" She had no chance of dodging it as it hit her square in the chest, falling backwards onto the ground. Harry looked away, he may have wanted revenge, but not to see her dead.

"Is that how you treat your servants Tom? Killing them when you don't get your way? If that's the case, you should have killed yourself a long time ago, I've defeated you four times so far, and tonight will be the fifth!" Harry spoke with as much confidence as he could muster.

"Is that so? Well then, let's see how well you do shall we, without any help," Voldemort said as he saw Dumbledore appearing from the fireplace. He quickly put up a barrier only he could break. Harry was trapped, and he knew it. Dumbledore tried to bring the barrier down, but it could not be done. Harry had to face the dark lord alone.

"We bow Harry." Voldemort bowed low and Harry reluctantly did the same. If he was going to die tonight, he was going to do down fighting. Harry and Voldemort cast their spells at the same time, the spells connecting in the middle, just like it did in the graveyard the previous year. This time however, Voldemort was prepared, breaking it off as soon as it connected and sent a cutting curse at Harry's arm, the flesh cutting from his elbow to his shoulder. Harry hissed in pain, furious with himself that he allowed Voldemort to breach his defence so early into the duel.

Harry wasn't going to give up though. Almost immediately, he countered with a stunning spell which connected with Voldemort's shield, followed up with three bone breakers in quick succession, two hitting the shield, one sneaking its way through and connecting with Voldemort's wand hand. Voldemort gave out a almighty scream as his hand looked all mangled, his wand soaring from one hand to another, continuing the duel.

Whilst this was happening, a crowd was forming in the ministry. The Minister of Magic had turned up, followed by all the aurors and the head of the DMLE, Madame Bones. Worst of all was Sirius, conscious and doing everything he could to bring the barrier down.

"Dumbledore! Help him, please! I can't lose him, not now!" Sirius practically begged of the old headmaster.

"I can't, I'm sorry, it looks like Harry is on his own." Dumbledore looked as old as ever, sadness pouring off him in waves, for what the young man in front of him as had to go through. Secretly though, he was in sheer awe as to the magic he could feel with the place. Raw magical power was radiating from the two duelist, magic crackling in the air as their duel waged on.

Voldemort was stunned at the boy in front of him. How was it that a mere 15 year old boy was able to stand toe to toe with him and match everything he threw at him. He put more power into the spells, wanting to wear the boy down enough to strike with the final blow. He saw the people in the Atrium. 'Good,' he thought to himself, 'They can see their precious golden boy fall to my power! Then they will all have to bow down to me!' He flung a killing curse at Harry, which he blocked by accio'ing a statue into the spells path, rubble blasting in each way as the spell connected.

Harry was concerned with how this duel was going. He needed to end it soon if he had any chance of getting out of here alive. Dodging killing curse after killing curse was tiring. Voldemort fired a black spell at him which he threw up a shield too. But instead of it impacting on the shield, it sucked back into him like a vacuum collecting dust. The build-up was gradually growing, until it couldn't hold no more, and came blasting back out, knocking Harry and the people outside of the barrier down to the ground. The glass from the offices all smashed, raining down on them both. Voldemort raised his arm, the glass rising up, forming a giant ball above of him, then flying back to Harry, with only one purpose in mind. Before it could do much damage, Harry raised another shield, the glass passing through, turning to sand. Harry had to look away, to avoid getting the sand in his eyes and being at an disadvantage.

Harry was growing more tired with every spell that he cast. He couldn't go on forever and he knew it. Voldemort knew it too. He had the upper hand, he could end it anytime he liked.

"You grow tired Harry, why don't you just stop now and throw down your wand, I'll make your death as painless as possible," Voldemort sneered from across the Atrium.

"Never! I will never give up to you! I will fight you with my dying breath!" Harry shot back, not about to give in to Voldemort's demands, while flinging out off the way of a killing curse.

"Then you leave me no choice Potter, Sectumsempra!" Voldemort's spell hit Harry in the lower abdomen while Harry was dodging the killing curse and Harry fell to the ground clutching at his stomach. "Expelliarmus." Harry felt his wand fly from him. He was defenceless. "Ha-Ha! Is that all you've got Potter? I was hoping you would put up a bit more of a fig…" Voldemort never got to finish that sentence. While he was talking, Harry pulled a second wand from his pocket and sent the strongest cutting curse at Voldemort. Voldemort's neck had been slashed and blood was pouring fast. Voldemort fell to the ground, gurgling, until a heave silence was heard and the barrier came down. Voldemort was dead.

"Harry!" Sirius was first in, hoping it wasn't too late to save his godson, Dumbledore right behind him. Harry was ghostly pale; a pool of blood was forming around his body.

"Professor please, save him!" Ron begged, Hermione weeping onto his shoulder at seeing her best friend in so much pain. Dumbledore started speaking the counter-curse, the cuts sowing back up, little colour coming back into his face.

Dumbledore picked up the statue head that was hit with the killing curse. "Portus!" Dumbledore whispered. "Hold on to him Sirius, it will take him to the hospital wing at Hogwarts, tell Poppy what has happened, she will help, I will come along as soon as I can. Children, crowd round and go with him, he will need you there! One… two… three." A bright blue light flashed and Sirius felt himself flying around. They were going back to Hogwarts.

**That's the first chapter up. Not sure how long I want this story to be yet, probably round 20,000 – 30,000 words with it being my first one. Please review, in desperate need to improve. Till next time!**


	2. Chapter 2

**Disclaimer: ****I do not own Harry Potter and NCI**

**Hi! Apologies for leaving this so late to upload, been watching 24 non-stop! Here it is though. Thanks for everyone who has followed and favourite.**

Albus Dumbledore was not a man who was easily worried. But seeing one of his favourite pupils go back to Hogwarts with life-threatening injuries gave the man so much worry and sorrow. Moments ago, he saw Harry defeat Voldemort. Something Dumbledore always knew Harry would do. Hearing someone call him, he turned around and faced the Minister of Magic, Cornelius Fudge.

"Dumbledore! How… what… I don't understand," Fudge stated weakly. Dumbledore sighed and looked around. He saw Aurors surrounding Voldemorts body, and Aurors walking down to the Department of Mysteries to retrieve the captured death eaters. Bellatrixs body was moved next to Voldemorts.

"The reason you don't understand is quite simply your own fault!" Dumbledore stated angrily. "All this shouldn't have happened! This rest solely on your hands!"

To say Fudge was annoyed was an understatement. "Now, look here Dumbledore! You can't talk to me like that! I'm the minister of magic, you can't go shouting at me like that! I ought to have you arrested!"

"Don't give me that Cornelius! If you had listened to me and Harry back in June, all of this could have been avoided; instead you decide to label us insane and attention seeking in a bid to save your minister role! But after today, I can't see you keeping it after death eaters and Voldemort himself broke into the Ministry.

"You have been blinded by the power that your office can give you! You should have listened to reason. I'm sorry Cornelius, I cannot help you, you have dug yourself a grave you have no hope of getting out off." With a pat to Fudge's shoulder, Dumbledore walked away, leaving the soon to be ex-minister of magic to wonder where it had all gone wrong.

While Dumbledore was talking to Fudge, Amelia Bones, head of the DMLE led a group of aurors down to the Department of Mysteries to round up the captured death eaters. In that group, were Tonks and Kingsley Shacklebolt. Amelia requested these two, because they were part of the group that fought the death eaters head on.

"Do you know who it is has been caught down here Shack?" Amelia inquired, wanting to know just how many death eaters had been caught.

"At least twelve have been caught Amelia, the weird thing was, at one point, they all collapsed, holding their arms. At the time, I couldn't understand why, but now I do." Kingsley replied in his deep tone.

"Yeah, we all owe Harry for what he has done. To have thought the darkest wizard in decades and come out on top is a miracle!" Tonks piped in.

"At a price though. I don't think I've ever seen Dumbledore so worried than I did when he saw what injuries Mr Potter has picked up from this. I will have to pay him a visit when he gets better." Amelia knew just how deadly Voldemort was. She had seen the devastation he caused up close during the first wizarding war. "Where are they being held Tonks?" She asked off the captured death eaters.

"In the death Chamber, Alastor offered to keep an eye on them." They rounded the corner and entered the chamber. The death eaters were sitting in the middle of the room near the veil, bounded in thick ropes. Next to them Alastor Moody stood, wand trained on them, in case any of them broke free.

"Amelia, bout time you got here! This lot need to be shipped off to Ministry holding as soon as possible. What if one of them escaped and attacked people? Can never be too careful when you're dealing with death eaters." Moody snapped.

"Sorry Alastor, had to deal with the fallout upstairs. Ok you lot!" Amelia shouted at the aurors, "take this pile of scum to the holding cells, I'm sure they're wanting to get to their luxury cells at Azkaban."

"Bah, lock us up, but we'll run free again soon, and when we do, we will continue our masters work!" one of the death eaters sneered at Amelia which she noted was Lucius Malfoy. Instead off relatiating, she turned and looked around at the devastation that surrounded her. Broken bits of rock, blood smeered on the walls, one hell of a fight happened here, and she was just glad no-one was too seriously hurt.

"Madam Bone, quickly over here!" Amelia turned quickly and rushed over to were Shacklebolt was with a prisoner.

"What's the problem Shack?" She asked off the tall auror who was looking at the death eater with disdain. Shack didn't reply, instead pulled off the death eaters hood. Amelia's eyes grew to the size of saucepans. "I think Dumbledore needs to see this."

Poppy Pomfrey was tired. She was up all night after hearing about the battle happening at the Department of Mysteries, and stayed alert for the first sign of someone entering who needs medical assistance. About two hours after hearing the noise, a noise made her look up. She could tell who it was. It was Sirius Black and Remus Lupin, with the school children who had gone to the Department of Mysteries. Upon further observation, she saw Sirius clinging on to someone. Someone with black mess hair, and a lightning bolt scar above their head.

As soon as Poppy saw this, she sprung into action, rushing over to them, silently bringing medical gear over with her.

"Poppy, please help him, his cuts won't stop bleeding!" Sirius all but begged the medi-witch who walked over to them wand at the ready.

"Put him over here quickly." She led him over to Harry's official bed in the hospital wing and started to work on him as soon as he hit the bed. "I need you to back up and let me work. I can't do this if you're going to crowd me!" Sirius waved everyone back, knowing that Madam Pomfrey needed to do some serious work to save his godson.

Sirius looked around in a daze. The last half hour have been the worst in his life. He just witnessed the only family he had, bar Remus, go head to head with Voldemort and come out with serious injury. He knew that if Voldemort wasn't already dead, he would kill him himself for what he has put Harry through the last 15 years. He was so caught up in it all, that he didn't notice Hermione come up next to him.

"Sirius?" No answer. "Sirius?" Slowly, he turns to look at her, seeing the red eyes and tear marks that run down her face. "Please tell me he's going to be OK. I don't want to lose him. He's my best friend." Sirius didn't say anything. Instead he wrapped his arms around her and held her as she cried for her friend on the verge of death.

Approximately two hours later, Madam Pomfrey came out, looking grim. "I've done all I can. I've gave him blood-replenishing potion and tried to heal the cuts, but they won't fully close. I've know someone who has seen something like this though. He should be able to help."

Sirius at once jumped at the chance at someone saving his godson. "Great! Who is it? Can they get here right now?"

"I think she is referring to me, Black," a sneer sounded from behind him. Sirius whirled around, and came face to face with Severus Snape.

Sirius went from frantic to angry in a matter of seconds." You? You think you can just walk here and help him? Why you? Why not someone else?" he demanded of the man he despised.

"I think the answer should be obvious, even for your tiny mind to understand." Snape's expression didn't change. "Regardless of what you may think, I don't hate the boy enough to just stand by and not do anything. I know the counter curse to the spell the dark lord put on him. He should be fine, but he won't be if you don't get out of my way!" Reluctantly, Sirius stepped aside, but before Snape could take two steps forward, Sirius took hold of his arm.

"If I find out you've harmed him in any way. I will kill you." Without another word, Snape wrestled free of Sirius's grasp and continued towards the hospital wing.

Sirius sat back down and put his head in his hands. Next thing he knew, he was being shaken by Remus.

"Padfoot, Snape just left, Harry's going to be fine. Poppy thinks he's going to wake up tomorrow." Sirus's entire face lit up with happiness and gave Remus a hug of sheer delight.

Footsteps coming down the corridor alerted Sirius of company and stood to see who it was. He certainly didn't expect to see Dumbledore and Amelia Bones rushing down the corridor towards him. Remus took a protective stance in front of him, as did Ron, Hermione and Ron. Neville and Luna stood to the side, unsure of what was happening.

"How's Harry?" Dumbledore asked as soon as he was in range of them, worry etched on his face and his signature twinkle non-existent in his eye.

"He will be ok, Severus has just been to see him, Poppy thinks he will wake up tomorrow morning at the earliest." Remus explained, Dumbledore's face brightened up exceptionally from hearing that. "But please don't even think about taking Sirius anywhere!"

Dumbledore and Amelia looked at eachother. Amelia stepped forward and held out a piece of parchment. "Mr Black, this is for you. It's a summons to a trail so we can find out the truth of what happened fifteen years ago."

To say Sirius was shocked was an understatement. Dumbledore had a smile on his face as he gave Sirius the second best news he heard within the last five minutes.

"Sirius, we've captured Peter Pettigrew!"

**And I think I will leave it there. I know some of you were hoping for longer chapters, but I'm working up to that, so at the moment, each chapter will be between 1,500-2,000 words long. Big thanks to everyone who reviewed. Again, please leave reviews for me, still got a lot to learn. Thanks!**

**HarrytheAvenger.**


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